SRD:Summon Monster III

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One or more summoned creatures, no two of which can be more than 30 ft. apart

This spell functions like summon monster I, except that you can summon one creature from the 3rd-level list, 1d3 creatures of the same kind from the 2nd-level list, or 1d4+1 creatures of the same kind from the 1st-level list.